Let's say a cyclist hits a tree and fractures his arm. Which of the following would have likely prevented the fracture: a) decrease in his velocity by factor of 2 b) decrease in his mass by factor of 2 What arguments can be used here to reason this (ex. momentum, energy, force)? Immediately when I rephrased the question in my head to what change would have reduced the damage the most and thought of force. However, I guess you could also use the kinetic energy argument. I'm a little confused as to what the correct way to approach this is. At any rate, shouldn't all arguments lead to the same conclusion? Thanks.